The present invention relates to wide area communication systems and more particularly to systems in which each of multiple data terminals, such as point-of-sale terminals in the form of transaction or credit card readers, is to be linked to its host computer selected from a group of multiple computers.
Wide area business communication networks are employed to connect one or more centralized data/communication centers to multiple remote stations or offices to which data and/or other communication links need to be established. For example, a private communication system may be established as a wide area network in which a company data center is linked with branch offices of the company across a wide geographic area.
The wide area network (WAN) may have any of various system designs. Thus, point-of-sale terminals may be interfaced with the public telephone system thereby establishing a wired terrestial wide area network. A more technologically advanced and often more commercially advantageous network is one in which satellite communications provide the communication links.
One satellite wide area network (SWAN) that is commercially available is called the Integrated Satellite Business Network.TM. supplied by Hughes Network Systems, Inc. In the Hughes SWAN, a hub station is located at a central location and a very small aperture terminal called a Personal Earth Station.TM. is located at each remote site.
In the prior art, point-of-sale terminals such as transaction card readers have used the public telephone network to gain access to one of possibly several host computers. A telephone call is placed from the card reader either automatically upon a credit, cash or other card being swiped through the reader, or manually by the user entering dial digits through a keypad.
Card readers normally have an integral or external modem that provides an interface to a traditional telephone circuit. As a result, connection of card readers to a WAN through a digital interface, such as an RS232 interface, has been problematic. Thus, the card-reader modem expects to interface a telephone circuit while the WAN equipment expects to interface digital terminal equipment (DTE).
Moreover, some data communication networks for point-of-sale terminals such as card readers can connect each point-of-sale terminal in the system to a predesignated host computer for ultimate exchange of data between the card reader and the specific host computer that contains data for a card being read by the card reader. As a result, access to data bases on host computers other than the predesignated host computer is prohibited or made difficult. For example, in such networks, access of a point-of-sale terminal is restricted to only one provider of credit card verification services through the predesignated host computers. In addition to restricting data base services, such networks have processed transactions to link with their respective host computers with a requirement for excessive and costly computer hardware and with excessive communication network loading and excessive processing cost.
The present invention accordingly is directed to linking data terminals or point-of-sale terminals such as card readers having an integral or external modem to a WAN without use of telephone circuitry and thereafter to a host computer through the WAN with improved efficiency and economy.